Folic acid and vitamin B<sub>12</sub> in reproducing sows: New concepts
Bibliographic record
Abstract
In pig nutrition, the present gaps in the information on B-complex vitamins have important implications for empiricism and disparities in dietary recommendations. This is particularly true for folic acid (B 9 ) and vitamin B 12 . Recent studies suggest that the beneficial effects of B 9 on sow prolificacy may be due to enhanced embryo development and survival. Embryo synthesis of estrogens and uterine secretions of prostanoids and cytokines during attachment appear to be key factors in vitamin B 9 regulation of embryo development. Nevertheless, embryo and uterine responses to B 9 are often more pronounced in multiparous sows than in gilts. This parity effect on B 9 responses can be attributed to the metabolic interaction with another vitamin, specifically B 12 . The two vitamins are essential for modulating the transfer of one-carbon groups for protein and DNA synthesis, methylation and gene expression. The metabolic pathway involved is the remethylation of methionine from an intermediary metabolite, homocysteine. A deficiency in B 9 or B 12 mayinduce a local or systemic accumulation of homocysteine, a powerful pro-oxidant known to impair embryo development. It appears that B 12 status, which is about two times lower in gilts than in multiparous sows, could be a limiting factor for the action of vitamin B 9 on uterus and embryo metabolism during the first pregnancy. Vitamin B 12 status is particularly critical since, in early gestation, the sow uterus drains off a massive amount of B 12 , representing two to three times the B 12 plasma pool. Dietary B 12 , at levels 10 times higher than recommended, have been found to maximize B 12 status and minimize homocysteine accumulation in first parity sows. It appears that an optimum B 9 :B 12 ratio, which has yet to be estimated, would enable vitamin B 9 to have full beneficial effects on sow prolificacy. In the future, it is likely that there will be an even greater need for updated information on the requirements for B-complex vitamins given the “dietary fine tuning” that is necessary for the highly producing pigs that have been selected in recent decades. Key words: Folic acid, vitamin B 12 , reproduction, pig
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".